1. Field of the Invention
The present invention relates to a so-called retractable barrel camera which is arranged such that a lens barrel of zoom system can be retracted into a camera body, and more particularly to a control in retracting the lens barrel.
2. Related Background Art
A recent demand is to reduce the outer dimensions of camera, particularly of compact camera. Especially, an important subject is to miniaturize a lens barrel as much as possible. To miniaturize the lens barrel, a recent trend in camera having the two-lens-group zoom system is to replace a mechanical cam system with a mechanism for driving the front lens group and the rear lens group by separate motors.
An example of the two lens group zoom system is one as shown in FIGS. 1A and 1B. A lens barrel 4 of the zoom system 2 is composed of a stationary barrel 6 forming a part of camera body 7, an intermediate barrel 8 telescopically stored in the stationary barrel 6, and a movable barrel 10 telescopically stored in the intermediate barrel 8.
A front lens group (FLG) 22 which consists of one or more lenses is fixed in a front end portion of the moving barrel 10 and is arranged to be driven by a direct current (DC) motor (not shown in FIGS. 1A and 1B) to move backward and forward together with the moving barrel 10.
Also, a rear lens group (RLG) 28 which consists of one or more lenses is arranged behind the front lens group 22 (on the camera body side) in the moving barrel 10 so as to be movable backward and forward. The rear lens group 28 is driven backward and forward by a stepping motor (not shown in FIGS. 1A and 1B).
FIG. 1A indicates an extreme telephoto state in which the focal length is longest and FIG. 1B indicates an extreme wide-angle state in which the focal length is shortest.
It is general in the two-group zoom system 2 as described above that in a non-photographic condition the moving barrel 10 and intermediate barrel 8 are further retracted into the stationary barrel 6 from the extreme wide-angle state to store the entire lens barrel 4 at the retracted position in the camera body.
However, for example, if the lens barrel 4 is moved to the retracted position while keeping the rear lens group 28 at the position in the extreme wide-angle state, the rear lens group 28 could come into contact with a film F so as to result in damaging the film F. It can be contemplated in order to solve such a problem that before the lens barrel 4 is stored in the camera body, the rear lens group 28 is first moved to a predetermined standby position close to the front lens group 22 and that thereafter the lens barrel 4 starts being retracted.
Starting the lens barrel storage process, this method, however, takes a considerable time for moving the rear lens group 28 to the forward standby position, for example if the zoom system 2 was in the extreme wide-angle state, which could give a user such an impression that the camera is out of operation during the time before the lens barrel 4 starts moving.